Respected Rabbi Marc Schneier has split from his fourth wife and is now spending time with a younger woman.

A source tells us the rabbi and wife Tobi Rubinstein-Schneier are divorcing after splitting a few months ago, and he has since started spending time with an attractive brunette in her 30s named Gitty.

Schneier, founding rabbi of the New York Synagogue and the Hampton Synagogue in Westhampton, is also a spiritual adviser to stars including Russell Simmons and Steven Spielberg. He and Tobi have been married for three years.

Schneier, 51, is also the founder and president of the Foundation for Ethnic Understanding. He often jets around the world to improve interfaith relations and met with Pope Benedict at the Vatican last year.

Schneier, named by Newsweek as one of the 50 most influential American rabbis, recently told his congregation that he’s suffering from bipolar disorder.

A source told us: “He’s divorcing his fourth wife. He’s a great leader in the Jewish community, he’s just not very good at marriage.

“He met Gitty after he was separated from Tobi and they are spending time together.”

A spokesman for Rabbi Schneier, Ken Sunshine, said: “Marc Schneier is a renowned worldwide leader, and a pioneer in Muslim-Jewish relations. He has been dealing with a very serious illness, and we will have no comment on rumor or innuendo.”

Schneier has written and spoken extensively on intergroup relations, and is a frequent guest on television and radiotalk shows. He is the author of the book, Shared Dreams, an account of the relationship between the Reverend Dr. Martin Luther King, Jr. and the Jewish community during the civil rights era, published in January, 2000; the Foundation for Ethnic Understanding, which he founded with Joseph Papp and is chaired by Hip hop mogul Russell Simmons, produced a student guide based on the book which was distributed to thousands of Jewish and black students in hundreds of high schools and colleges in the United States.

A New York City orthodox rabbi says his popularity at the White House is probably due to his outreach efforts in the Muslim world.

Rabbi Marc Schneier, is one of the very few Orthodox guests reported to be on the list for an upcoming White House reception celebrating Jewish Heritage Month.

…Other than Schneier, few — if any — are expected to be Orthodox Jews or rabbinical scholars. The rabbi, who heads two congregations in the Big Apple and spoke at the 2008 Democratic Convention, told the Associated Press that he believes he was invited for political reasons. Rabbi Schneier is president of the Foundation for Ethnic Understanding, an interfaith group he founded in 1989 with the late Joseph Papp. He also has a long track record in building ties with the black community, both in New York and nationwide.